Understanding IP Addressing
Every computer that communicates over the Internet is assigned an IP address that uniquely identifies the device and distinguishes it from other computers on the Internet.
What is an IP Address?
Recommended Reading: Learn more about the TCP/IP protocol.
An IP address consists of 32 bits, often shown as 4 octets of numbers from 0-255 represented in decimal form instead of binary form. For example, the IP address: 188.8.131.52 in binary form is 10101000.11010100.11100010.11001100.
But it is easier for us to remember decimals than it is to remember binary numbers, so we use decimals to represent the IP addresses when describing them. However, the binary number is important because that will determine which class of network the IP address belongs to.
The Two Parts of an IP Address
The Class of the address determines which part belongs to the network address and which part belongs to the node address. All nodes on a given network share the same network prefix but must have a unique host number.
Class A Network
In a Class A Network binary address start with 0, therefore the decimal number can be anywhere from 1 to 126. The first 8 bits (the first octet) identify the network and the remaining 24 bits indicate the host within the network. An example of a Class A IP address is 184.108.40.206, where "102" identifies the network and "168.212.226" identifies the host on that network.
Class B Network
In a Class B Network, binary addresses start with 10, therefore the decimal number can be anywhere from 128 to 191. The number 127 is reserved for loopback and is used for internal testing on the local machine. The first 16 bits (the first two octets) identify the network and the remaining 16 bits indicate the host within the network. An example of a Class B IP address is 220.127.116.11 where "168.212" identifies the network and "226.204" identifies the host on that network.
Class C Network
Binary addresses start with 110, therefore the decimal number can be anywhere from 192 to 223. The first 24 bits (the first three octets) identify the network and the remaining 8 bits indicate the host within the network. An example of a Class C IP address is 18.104.22.168 where "200.168.212" identifies the network and "226" identifies the host on that network.
Class D Network
In a Class D Network, binary addresses start with 1110, therefore the decimal number can be anywhere from 224 to 239. Class D networks are used to support multicasting.
Class E Network
In a Class E Network, binary addresses start with 1111, therefore the decimal number can be anywhere from 240 to 255. Class E networks are used for experimentation. They have never been documented or utilized in a standard way.
Creating desktop shortcuts to a websites is useful. When you double-click the icon from your desktop it automatically launches the browser and... Read More »Flash Data Storage Vendor Trends
Although it is almost impossible to keep up with the pace of ongoing product releases, here are three recent highlights in the flash data storage... Read More »15 Important Big Data Facts for IT Professionals
Keeping track of big data trends, research and statistics gives IT professionals a solid foundation to plan big data projects. Here are 15... Read More »
- Check out eWeek's new Research Center, a central and comprehensive library of whitepapers, eBooks, eseminars, webcasts, and more from top industry brands and independent tech journalists »
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »
If hackers get their hands on your company's data, they can wreak havoc on customer relationships and cause tremendous damage to your brand and... Read More »Windows XP: Move Along, There's Nothing to See Here
After more than 12 years of holding the title of most popular operating system in the world, Windows XP is taking center stage for its final... Read More »Report: The Role of Big Data in the Marketing Industry
According to a new study from Infogroup Targeting Solutions, we can expect to see companies spend heavily on big data marketing initiatives in... Read More »